A microfiche appendix (Appendix 1) containing a total of 3 sheets and 201 frames of microfiche is included in this application.
The invention relates to a computer imaging system and method for detecting changing skin lesions and new skin lesions.
It is well known that rapid changes in the size of a mole or skin lesion may indicate the onset of precancerous or cancerous tissue growth and that early detection of such changes usually results in a much better prognosis for the patient, especially if the lesion is a melanoma. In the case of a melanoma, a delay of a month or two in detection may make the difference between successful treatment or death of the patient. Unfortunately, most people have difficulty detecting early changes in the size of a skin lesion because initial changes in size are slow and subtle. Furthermore, a physician observing a lesion usually does not have prior xe2x80x9cbaselinexe2x80x9d or reference information on the lesion from which to judge the amount or rate of its growth.
Because there is no generally effective treatment for metastatic melanoma, even small cancers often prove fatal if not detected early. This is unfortunate, because few cancers provide a greater opportunity for early discovery and removal than melanoma, because cutaneous melanoma (1) is located on the skin surface where it is readily observed, and (2) usually undergoes an easily observable xe2x80x9cradial growthxe2x80x9d phase prior to metastasis.
The radial growth stage of a cancerous skin lesion therefore provides a window of opportunity during which the lesion can be detected and removed before metastasis, with a high probability of a complete cure.
The closest prior art is believed to be our publication xe2x80x9cVideo Comparator System for Early Detection of Cutaneous Malignant Melanomaxe2x80x9d, SPIE vol. 1653/Image Capture Formatting, and Display (1992). Various difficulties were encountered in providing a practical implementation of the basic technique described in that article using a microcomputer-based video imaging system for storing an image archive of historical reference images for each patient, registering and scaling current images with baseline images, and using a blink comparison of the image pairs in a manner that is readily acceptable by and useable by patients. Those difficulties led to the present invention.
There clearly is a great need, which up till now has not been fulfilled, for an inexpensive, workable, accurate system and technique by which ordinary people can conveniently monitor the growth of skin lesions on their entire bodies and submit such information to a dermatologist who can then expertly observe lesions which have significantly changed since a prior examination. Nor has there been any available, accurate system and technique which can be used even by scientists and doctors to correctly and accurately quantify and/or record the development of lesions over time and/or to record the response of lesions to various treatments, especially on a large number of subjects; there clearly is a great need for such a system and technique.
Accordingly, it is an object of the invention to provide an inexpensive, easily used system/method for detecting new skin lesions and/or skin lesions which have grown significantly.
It is another object of the invention to provide such a system for establishing a baseline record of image data of initial skin conditions and providing a meaningful comparison of later images of the same skin areas with the baseline images so as to readily and accurately identify all new lesions or pre-existing lesions which have significantly grown.
It is another object of the invention to provide such a system that allows patients to simply take photographs of their skin in the privacy of their homes and to use ordinary personal computers to identify new or significantly growing lesions on the basis of the information in such photographs.
It is another object of the invention to provide a quick, convenient way to align an image in good registration with another image, which may be of essentially the same subject matter, without introducing distortions in either image.
It is another object of the invention to provide a research tool to enable study and quantification of the natural history of skin lesions.
It is another object of the invention to provide a research tool to enable convenient study of the effects of various skin treatments on the human skin and lesions thereon.
Briefly described, and in accordance with one embodiment thereof, the invention provides a method of identifying new or growing skin lesions by providing digital baseline image data of an area of a subject""s skin, and storing the baseline image data. An imaging system is operated to produce current digital image data of the skin area directly from the subject or from a photograph thereof as an input to a computer, and storing the baseline image data in the computer. The current image data and baseline image data are alternately displayed in an alternating display of selectable frequency on a monitor associated with the computer. The orientation, focus, and/or distance of the camera from the actual area or photograph thereof are adjusted so as to align images of two or more corresponding but separated features of the alternately displayed images. A frame of the aligned current image data is digitized and stored with the baseline image data. The stored aligned current image data and the baseline image data are alternatively displayed in a blinking (alternating) mode on a monitor to visually identify lesions which appear to flash on and off, or to pulsate, to thereby identify new and/or significantly growing/changing lesions. The subject then can have a dermatologist observe the identified lesions.